DCS is a free-to-play combat flight simulator that have many pricey add-on modules. They add planes, helicopters, maps and missions. Most of the aircraft's are insanely detailed both in how they look and work. Mission sometimes end with me down in the cockpit, flipping switches, turning knobs, and then crashing into a building. A-10C Warthog and Black Shark 2 in co-op is my add-ons of choice. In easy mode so I can focus on the knobs.